The Monster Energy NASCAR Cup Series (MENCS) is the top racing series of the National Association for Stock Car Auto Racing (NASCAR). Since 2017, it has been named for its sponsor, Monster Energy, but has been known by other names in the past. The series began in 1949 as the Strictly Stock Division, and from 1950 to 1970 it was known as the Grand National Division. In 1971, when the series began leasing its naming rights to the R. J. Reynolds Tobacco Company, it was referred to as the Winston Cup Series. A similar deal was made with Nextel in 2003, and it became the Nextel Cup Series (2004–2007). Sprint acquired Nextel in 2005, and in 2008 the series was renamed the Sprint Cup Series, which lasted until 2016. In December 2016, it was announced that Monster Energy would become the new title sponsor starting in 2017.